Razor blade sharpener



A E'. T. KNIT-fm 2,381,669

Aug. 7, 1945.

RAZOR BLADE SHARPENER Filed NOV. 25,l 1945 INVENTQR. ELMER 7." KN/TTEE [.54 l; ATTORNEY.

Patented Aug. 7, 1945 UNITED STATES PATENT OFFICE RAzoa BLADE SHARPENER l 'Elmer T. Kilmer, Redwood City, Calif. Appnoation Novemboras, 194s, soriauvo; 5114.401 10 Claims. (Cl. `5159) My invention relates to blade sharpeners, and

`particularly to those suitable for sharpening safety razor blades.

One of the objects of my invention is to provide a blade sharpener capable of working successively on both sides of the blade once the blade isplaced in the device.

, Another object of my invention is to provide a gravity and inertia actuated sharpening device in which `a pair of abrasive members sup- 1 port the blade each against the other and act in succession on the opposite edges of the blade.

Another object of my invention is to provide a bladesharpenng device which has a minimum of parts and is economical to manufacture and easy to use and maintain.

For the purpose of compliance with U. S. Revised Statutes Sec. 4.888 I shall describe one form in which my invention may be embodied, and by which the above and other objects may be obtained. Y It is not my intention to limit my invention to the` particular form of the parts used in this description. In the drawing, Fig. 1 is a view in perspective with some of the parts broken away to show the assembly and interrelation of parts; y

Fig.' 2'is a view in cross-section showing the relation ofthe parts at the end of the left stroke of the abrasive members; fFig. 3 is a cross-sectional. View showing the parts withthe right stroke partially 'completed;`.

Fig. 4 is a similar view as the right stroke is nearing completion;

Fig. 5 is a similar view at the end of the right stroke Fig. 6 is` a similar view with the left stroke partially completed;

Fig. 7 isA an enlarged View similar to Fig. 2;

Fig. 8 is a cross-sectional -view taken on the line 8--8 of Fig, 3 but With the locking member 60 removed;

` Fig. 9 is a top plan view of the device with the upper'welghted abrasive member removed;

Fig. 10 is a bottom plan view of the upper weighted abrasive member;

reduced cylindrical portion 28. The latter portion is made of `a size suitable to extend into slot-s 30 found on most razor blades whether they are the double edge type shown in Fig. 9, or single edge type shown in Fig. 11. The blade holding studs 25 maybe secured to the base 2| in any suitable manner. such as by riveting as shown at 3l. The width of base 2| between Iianges 24 as shown in Fig. 8 is such as to allow a clearance 32 between the flanges and the Weighted movable abrasive members.

In the frame 20 are supported a pair of weighted abrasive members 48 and 4 I. The lower abrasive member 40 is formed with a pair of elongated slots 42 (see Fig. '1) adapted to slldeably engage around the cylindrical portion 21 of studs 25. These slots permit the gravity or inertia impelledmovement of abrasive member 40 across the floor or base 2l of frame 20. The ledges 26 on each stud25 impart a rocking motion to abrasive member 40 as it moves from side to side as shown by comparing its position in Figs. 2 and 5. The abrasive member 40 may be made of any lsuitable material having the characteristic of `flexed into the shape shown in Fig. '1. The abrasive member 40 is also provided near each edge with a ledge 41, which ledges are spaced relative to the ends of the slots 42 so that When abrasive Fig. 11` is a plan View of another form of razor member 48 rests with one end of slot 42 against cylindrical portion 21 of stud 25 its adjacent ledge 41 will be under and inside the end 48 of the razor blade whereby the blade 46 is lifted above the level of ledge 41 Where it can be engaged by the abrasive surface on the other abrasive'memberl I. This is shown on the right hand side of Fig. '1, and also in Figs. 2, 3, 5 and 6.

The other abrasive member 4| has its abrasive surfaces 5l shaped to fit the edges 52 of the flexed razor blade 46 when the latter is supported on ledge 41 in position to be engaged by the upper abrasive member (see Fig. 7). With certain blades it'is desirable to flex them during the sharpening operation. This is accomplished by means of a projecting ledge 53 on the bottom side of abrasive member 4l (see Fig. 10); 'I'he latter is held in the frame 2D by the studs 25 which extend throughl holes 54. The diameter of these holes is larger than the cylindrical extension 28 of stud 25 sothat abrasive member 4| can move from right to left as shown in Figs. 2 to 7. I prefer that the movement permitted abrasive member 4I by the holes 54 shall be less than the movement permitted the other abrasive member 40 by its slots 42. The reason for thisl will soon become apparent.

If carefully handled while sharpening a blade, the abrasive plates 40 and 4l will remain in position on studs 25, but to insure against their becoming detached or thrown out of position, I4

provide a locking member 60 having hole 6I to engage with the upper end of one stud 25 while a spring pressed detent 62 engages the other stud 25 (see Fig. 8).

In Figs. 2 to 6 I have illustrated different stages in the grinding cycle. In the first place, when it is desired to sharpen a blade the upper abrasive plate 4l is lifted off and the blade is placedinthe position shown in Fig. 9; resting against the abrasive surface 43 of abrasive member 40. Then the upper abrasive member 4l is placed in position and the locking device 60 is secured across the pins. The frame is then held by the fingers in recesses 22 and a reciprocating stroke is imparted to the frame. This might be described as a swinging right to left motion such as would be given by a semaphoreor a wig-Wag. The effect of this wig-Wag motion is shown in the drawings. In Fig. 2, the frame is at the end of the left stroke of the abrasive members 40 and 4I which means that in relation to them the frame has been moved to the right. 'Ihe abrasive members 40 and 4l were impelled to the left by gravity or inertia. They are' shown resting against the stud 25 (see Figs. 2 and.7). The flexed blade 46 is supported with its right hand upper blade face 52 held in engagement with the abrasivesurface l ofthe upper abrasive member 4l by the ledge 4'( on the lower abrasive member 40. The device is now in position to grind blade surface 52. This it does as shown in Fig. 3 when the frame 20 is impelled to the left. The razor blade 46 is caused to move with frame 20 by means of stud 25. Due to the greater inertia which it must overcome to move vthe lower abrasive member 40, it does not begin its travel until the more easily moved upper abrasive member 4l has come to restagainst stud 25, This movement of the upper abrasive member 4l grinds the surface 52 of the blade while it is held supported by ledge 41 on the lower abrasive member. As the movement of frame 20 continues to theleft the inertia holding the lower abrasive memberin place is overcome and it too moves to the right relative to the frame thus causing a grinding of the lower faces 44 and 45 of razor blade 46 on the abrasive surfaces 43. This is shown in Fig. 4. Finally the movement of frame 20 to the left is sufficient to have caused a shifting of the abrasive member 40 all the way to the right and into the position shown in Fig. 5, The next cycle is now ready to start and the frame 25 is moved to the right causing the upper abrasive member 4I to move to the left and grind the upper face 52 of the razor blade. The other steps, as frame 20 is moved to the right, are the reverse of those illustrated in Figs. 3, 4 and 5. n,

By means of my blade sharpening device it is possible to engage in succession the two faces of the cutting edge of a blade by weighted gravityv impelled abrasive members 40 and 4I arranged one on each side of the blade and wherein each of these members 40 and 4I have respectively projecting means 41 and 53 which support the blade against the abrasive face of the other member during part of their movement and in whieh the studs 28 restrain the blade against as much shifting movement as the abrasive members 40 and 4l have in the frame.

While I have described a device in which the flexible razor blades are flexed downwardly in the center, the abrasive members may be shaped oppositely so that the blade is flexed upwardly. In other words, the abrasive members may be reversed and still retain my inventive concept. By fweighted abrasive member I mean one which has sufficient weight or inertia to be moved relative tothe frame when the latter is shaken back and forth in the hand.

' I claim: l

1. A sharpening device for operating on a safety razor blade, comprising a frame, with a pair of blade positioning means secured therein; a lower weighted abrasive member having a concave face in engagement with the blade edge during part of its movement and bordered by a ledge above which said blade comes to rest during the last part of its movement, and with elongated slots to receive said positioning means and to allow restricted relative movement of said member in said frame; and an upper weighted abrasive member with openings to receive said positioning means and to allow restricted relative movement of said upper member in said frame as well as in relation to said lower member.

2. A sharpening device for operating on a safety razor blade, comprising a frame, with a pair of blade positioning means secured therein; a lower weighted abrasive member having a concave face in engagement with the blade during part of its movement and ,bordered by aledge over which said blade extends during the last part of its movement, and with elongated slots to receive said positioning means and to allow restricted l relative movement of said member in said frame; and an upper weighted abrasive member having a flexing ridge to bow the blade to conform its cutting faces to the grinding contour of said member and slots to receive said positioning means and to allow restricted relative movement of said l upper member in said frame as well as in relation allow restricted relative movement of said member in said frame, and an upper weighted abrasive member having a iiexing ridge to bow the blade to conform its cutting faces -to the grinding contour of said member and with openings to receive said positioning means and to allow restricted relative movement of said upper member in said frame as well as in relation Ato said lower member.

4. A sharpening device for operating on a safety razor blade, comprising a frame, a pair of blade positioning studs secured therein, a-

lower weighted abrasive member with elongated slots to receive said studs and to allow restricted relative movement of said member in said frame, and an upper weighted abrasive member with means to allow restricted relative movement of said `upper member inl relation to said lower member.

5. A sharpening device for operating on a safety `razor blade comprising a frame, a pair of blade positioning studs secured therein, a weighted abrasive member with elongated slots to receive said studs and lto allow restricted rela.-

tive movement of said member in said frame, and another weighted abrasive member with openings lto receive said studs and to allow restricted relative movement of said member in said frame as well as in relation to said other member.

6. A sharpening device for operating on a safety razor blade, comprising a frame, with a pair of blade positioning studs secured therein, and a rocking ledge across the bottom of said frame; a lower weighted abrasive member with elongated slots to receive said studs and to allow restricted relative movement of said member in said frame; and an upper weighted abrasive member with openings to receive said studs and to allow restricted relative movement of said upper member in said frame as well as in relation to said lower member.

7. In a blade sharpening device adapted to engage in succession the two faces of the cutting edge, the combination of a frame, a pair of weighted abrasive members mounted to slide at a substantial angle tothe axis of said blade one on each side of said bladesaid members being moved generally crosswise relative to said frame and blade by their inertia when said frame is moved, each of said members having projecting means which support the blade against the abrasive face of the other member during part /of their movement, and means for restricting the blade against as much movement as the abrasive members have.

8. In a blade sharpening device adapted to engage in succession the two faces of the cutting edge, the combination of a frame, a pair of weighted abrasive members mounted Ito slide at a substantial angle to the axis of said blade one on each side of said blade said vmembers being moved generally crosswise relative to said frame and blade by their inertia when said frame is moved, each of said members having projecting means which support the blade against the abrasive face of the other member during part of their movement, means for restricting the blade against as much movement as the abrasive members have, and means for giving one abrasive member more movement relative to the blade than is given the other.

9..A sharpening device for operating on a safety razor blade, comprising a frame, blade positioning means therein, a lower weighted abrasive member with elongated slots to receive said positioning means and to allow restricted relative movement of said member in said frame, and an upper weighted abrasive member with means to allow restricted relative movement of said upper member in relation to said-lower member.

10. A sharpening device for operating on a safety razor blade, comprising a frame, a pair of blade positioning ymeans therein, a weighted abrasive member with elongated slots to receive said positioning means and -to allow restricted relative movement of said member in said frame, and another weighted abrasive member with openings to receive said positioning means and to allow relative movement of said member in said frame as well as in relation to said other member.

ELMER T. KNITTER. 

